title: A novel mutation in STXBP1 causing epileptic encephalopathy (late onset infantile spasms) with partial respiratory chain complex IV deficiency.
abstract: STXBP1 (MUNC18.1), encoding syntaxin binding protein 1, has been reported in Ohtahara syndrome, a rare epileptic encephalopathy with suppression burst pattern on EEG, in patients with infantile spasms and in a few patients with nonsyndromic mental retardation without epilepsy. We report a patient who presented late onset infantile spasms. Epilepsy was controlled but the patient developed severe mental delay. A first diagnosis of mitochondrial disease was based on clinical presentation and on a partial deficit of respiratory chain complex IV, but molecular screening for mitochondrial genes was negative. The sequencing of STXBP1 gene found a de novo nonsense mutation (c.585C>G/p.Tyr195X). This observation widens the clinical spectrum linked to STXBP1 mutations with the description of a patient with late onset infantile spasms. It raises the question of the value of epilepsy genes screening in patients with uncertain, partial or unconfirmed mitochondrial dysfunction.
authors.affiliation: Centre de Référence des Epilepsies Rares, Department of Paediatric Neurology, Hôpital Necker Enfants Malades, Inserm, U663, Paris, F-75015; University Paris Descartes, PRES Sorbonne Paris Cité, Paris, F-75005; CEA, Neurospin, 91190 Gif/Yvette, France.
authors.forename: G
authors.initials: G
authors.lastname: Barcia
authors.forename: C
authors.initials: C
authors.lastname: Barnerias
authors.forename: M
authors.initials: M
authors.lastname: Rio
authors.forename: K
authors.initials: K
authors.lastname: Siquier-Pernet
authors.forename: I
authors.initials: I
authors.lastname: Desguerre
authors.forename: L
authors.initials: L
authors.lastname: Colleaux
authors.forename: A
authors.initials: A
authors.lastname: Munnich
authors.forename: A
authors.initials: A
authors.lastname: Rotig
authors.forename: R
authors.initials: R
authors.lastname: Nabbout
mesh_terms: D058256:Brain Waves; D018389:Codon, Nonsense; D003576:Electron Transport Complex IV / Q000235:genetics*; D006801:Humans; D007223:Infant; D008607:Intellectual Disability / Q000175:diagnosis / Q000235:genetics*; D065768:Lennox Gastaut Syndrome; D008297:Male; D051938:Munc18 Proteins / Q000235:genetics*; D013036:Spasms, Infantile / Q000175:diagnosis / Q000235:genetics*
chemical_list: D018389:Codon, Nonsense; D051938:Munc18 Proteins; C497937:STXBP1 protein, human; D003576:Electron Transport Complex IV
keywords: Complex IV; Early epilepsy mental retardation; Respiratory chain deficit; STXBP1